scholarly journals Polo-like kinase 4 kinase activity limits centrosome overduplication by autoregulating its own stability

2010 ◽  
Vol 188 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Andrew J. Holland ◽  
Weijie Lan ◽  
Sherry Niessen ◽  
Heather Hoover ◽  
Don W. Cleveland
Keyword(s):  
Amino Acid ◽  
Kinase Activity ◽  
Chemical Genetics ◽  
Threshold Level ◽  
Genome Integrity ◽  
Centrosome Duplication ◽  
Animal Cells ◽  
Centriole Duplication ◽  
Chromosome Missegregation ◽  
Pericentriolar Material

Accurate control of the number of centrosomes, the major microtubule-organizing centers of animal cells, is critical for the maintenance of genome integrity. Abnormalities in centrosome number can promote errors in spindle formation that lead to subsequent chromosome missegregation, and extra centrosomes are found in many cancers. Centrosomes are comprised of a pair of centrioles surrounded by amorphous pericentriolar material, and centrosome duplication is controlled by centriole replication. Polo-like kinase 4 (Plk4) plays a key role in initiating centriole duplication, and overexpression of Plk4 promotes centriole overduplication and the formation of extra centrosomes. Using chemical genetics, we show that kinase-active Plk4 is inherently unstable and targeted for degradation. Plk4 is shown to multiply self-phosphorylate within a 24–amino acid phosphodegron. Phosphorylation of multiple sites is required for Plk4 instability, indicating a requirement for a threshold level of Plk4 kinase activity to promote its own destruction. We propose that kinase-mediated, autoregulated instability of Plk4 self-limits Plk4 activity so as to prevent centrosome amplification.

scholarly journals Autophosphorylation of Polo-like Kinase 4 and Its Role in Centriole Duplication

2010 ◽  
Vol 21 (4) ◽  
pp. 547-561 ◽  
Author(s):  
James E. Sillibourne ◽  
Frederik Tack ◽  
Nele Vloemans ◽  
An Boeckx ◽  
Sathiesan Thambirajah ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Kinase Activity ◽  
Proteasome Inhibition ◽  
Centrosome Duplication ◽  
Active Fraction ◽  
Kinase Activation ◽  
Centriole Duplication ◽  
M Phase ◽  
Mother Centriole ◽  
Daughter Centriole

Centrosome duplication occurs once every cell cycle in a strictly controlled manner. Polo-like kinase 4 (PLK4) is a key regulator of this process whose kinase activity is essential for centriole duplication. Here, we show that PLK4 autophosphorylation of serine S305 is a consequence of kinase activation and enables the active fraction to be identified in the cell. Active PLK4 is detectable on the replicating mother centriole in G1/S, with the proportion of active kinase increasing through interphase to reach a maximum in mitosis. Activation of PLK4 at the replicating daughter centriole is delayed until G2, but a level equivalent to the replicating mother centriole is achieved in M phase. Active PLK4 is regulated by the proteasome, because either proteasome inhibition or mutation of the degron motif of PLK4 results in the accumulation of S305-phosphorylated PLK4. Autophosphorylation probably plays a role in the process of centriole duplication, because mimicking S305 phosphorylation enhances the ability of overexpressed PLK4 to induce centriole amplification. Importantly, we show that S305-phosphorylated PLK4 is specifically sequestered at the centrosome contrary to the nonphosphorylated form. These data suggest that PLK4 activity is restricted to the centrosome to prevent aberrant centriole assembly and sustained kinase activity is required for centriole duplication.

scholarly journals Cep152 acts as a scaffold for recruitment of Plk4 and CPAP to the centrosome

2010 ◽  
Vol 191 (4) ◽  
pp. 731-739 ◽  
Author(s):  
Onur Cizmecioglu ◽  
Marc Arnold ◽  
Ramona Bahtz ◽  
Florian Settele ◽  
Lena Ehret ◽  
...  
Keyword(s):  
Centrosome Duplication ◽  
Loss Of Function ◽  
Mitotic Spindles ◽  
Centriole Duplication ◽  
Terminal Domain ◽  
Pericentriolar Material ◽  
Gain And Loss

Both gain and loss of function studies have identified the Polo-like kinase Plk4/Sak as a crucial regulator of centriole biogenesis, but the mechanisms governing centrosome duplication are incompletely understood. In this study, we show that the pericentriolar material protein, Cep152, interacts with the distinctive cryptic Polo-box of Plk4 via its N-terminal domain and is required for Plk4-induced centriole overduplication. Reduction of endogenous Cep152 levels results in a failure in centriole duplication, loss of centrioles, and formation of monopolar mitotic spindles. Interfering with Cep152 function prevents recruitment of Plk4 to the centrosome and promotes loss of CPAP, a protein required for the control of centriole length in Plk4-regulated centriole biogenesis. Our results suggest that Cep152 recruits Plk4 and CPAP to the centrosome to ensure a faithful centrosome duplication process.

scholarly journals PLK4-phosphorylated NEDD1 facilitates cartwheel assembly and centriole biogenesis initiations

2020 ◽  
Vol 220 (1) ◽  
Author(s):  
Wangfei Chi ◽  
Gang Wang ◽  
Guangwei Xin ◽  
Qing Jiang ◽  
Chuanmao Zhang
Keyword(s):  
Cell Cycle ◽  
Amino Acid ◽  
Amino Acid Residue ◽  
Centrosome Duplication ◽  
Spatiotemporal Regulation ◽  
Mother Centriole ◽  
Pericentriolar Material ◽  
Daughter Centriole

Centrosome duplication occurs under strict spatiotemporal regulation once per cell cycle, and it begins with cartwheel assembly and daughter centriole biogenesis at the lateral sites of the mother centrioles. However, although much of this process is understood, how centrosome duplication is initiated remains unclear. Here, we show that cartwheel assembly followed by daughter centriole biogenesis is initiated on the NEDD1-containing layer of the pericentriolar material (PCM) by the recruitment of SAS-6 to the mother centriole under the regulation of PLK4. We found that PLK4-mediated phosphorylation of NEDD1 at its S325 amino acid residue directly promotes both NEDD1 binding to SAS-6 and recruiting SAS-6 to the centrosome. Overexpression of phosphomimicking NEDD1 mutant S325E promoted cartwheel assembly and daughter centriole biogenesis initiations, whereas overexpression of nonphosphorylatable NEDD1 mutant S325A abolished the initiations. Collectively, our results demonstrate that PLK4-regulated NEDD1 facilitates initiation of the cartwheel assembly and of daughter centriole biogenesis in mammals.

scholarly journals Breaking the ties that bind: New advances in centrosome biology

2012 ◽  
Vol 197 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Balca R. Mardin ◽  
Elmar Schiebel
Keyword(s):  
Cell Cycle ◽  
Cancer Cells ◽  
Recent Work ◽  
Genomic Instability ◽  
Centrosome Duplication ◽  
Animal Cells ◽  
Microtubule Organizing Center ◽  
Centrosome Separation ◽  
Organizing Center ◽  
Pericentriolar Material

The centrosome, which consists of two centrioles and the surrounding pericentriolar material, is the primary microtubule-organizing center (MTOC) in animal cells. Like chromosomes, centrosomes duplicate once per cell cycle and defects that lead to abnormalities in the number of centrosomes result in genomic instability, a hallmark of most cancer cells. Increasing evidence suggests that the separation of the two centrioles (disengagement) is required for centrosome duplication. After centriole disengagement, a proteinaceous linker is established that still connects the two centrioles. In G2, this linker is resolved (centrosome separation), thereby allowing the centrosomes to separate and form the poles of the bipolar spindle. Recent work has identified new players that regulate these two processes and revealed unexpected mechanisms controlling the centrosome cycle.

scholarly journals Nudel Contributes to Microtubule Anchoring at the Mother Centriole and Is Involved in Both Dynein-dependent and -independent Centrosomal Protein Assembly

2006 ◽  
Vol 17 (2) ◽  
pp. 680-689 ◽  
Author(s):  
Jing Guo ◽  
Zhenye Yang ◽  
Wei Song ◽  
Qi Chen ◽  
Fubin Wang ◽  
...  
Keyword(s):  
Hela Cells ◽  
Cytoplasmic Dynein ◽  
Animal Cells ◽  
Microtubule Organizing Center ◽  
Centrosomal Protein ◽  
Centriole Duplication ◽  
Mother Centriole ◽  
Organizing Center ◽  
Pericentriolar Material ◽  
New Mother

The centrosome is the major microtubule-organizing center in animal cells. Although the cytoplasmic dynein regulator Nudel interacts with centrosomes, its role herein remains unclear. Here, we show that in Cos7 cells Nudel is a mother centriole protein with rapid turnover independent of dynein activity. During centriole duplication, Nudel targets to the new mother centriole later than ninein but earlier than dynactin. Its centrosome localization requires a C-terminal region that is essential for associations with dynein, dynactin, pericentriolar material (PCM)-1, pericentrin, and γ-tubulin. Overexpression of a mutant Nudel lacking this region, a treatment previously shown to inactivate dynein, dislocates centrosomal Lis1, dynactin, and PCM-1, with little influence on pericentrin and γ-tubulin in Cos7 and HeLa cells. Silencing Nudel in HeLa cells markedly decreases centrosomal targeting of all the aforementioned proteins. Silencing Nudel also represses centrosomal MT nucleation and anchoring. Furthermore, Nudel can interact with pericentrin independently of dynein. Our current results suggest that Nudel plays a role in both dynein-mediated centripetal transport of dynactin, Lis1, and PCM-1 as well as in dynein-independent centrosomal targeting of pericentrin and γ-tubulin. Moreover, Nudel seems to tether dynactin and dynein to the mother centriole for MT anchoring.

scholarly journals Daughter centrioles assemble preferentially towards the nuclear envelope in Drosophila syncytial embryos

2021 ◽  
Author(s):  
Neil Henry James Cunningham ◽  
Imene Bouhlel ◽  
Paul Thomas Conduit
Keyword(s):  
Nuclear Envelope ◽  
Single Mother ◽  
S Phase ◽  
Animal Cells ◽  
Simultaneous Formation ◽  
Centriole Duplication ◽  
External Cues ◽  
Mother Centriole ◽  
Pericentriolar Material ◽  
Daughter Centriole

Centrosomes are important organisers of microtubules within animal cells. They comprise a pair of centrioles surrounded by the pericentriolar material (PCM), which nucleates and organises the microtubules. To maintain centrosome numbers, centrioles must duplicate once and only once per cell cycle. During S-phase, a single new daughter centriole is built orthogonally on one side of each radially symmetric mother centriole. Mis-regulation of duplication can result in the simultaneous formation of multiple daughter centrioles around a single mother centriole, leading to centrosome amplification, a hallmark of cancer. It remains unclear how a single duplication site is established. It also remains unknown whether this site is pre-defined or randomly positioned around the mother centriole. Here, we show that within Drosophila syncytial embryos daughter centrioles preferentially assemble on the side of the mother facing the nuclear envelope, to which the centrosomes are closely attached. This positional preference is established early during duplication and remains stable throughout daughter centriole assembly, but is lost in centrosomes forced to lose their connection to the nuclear envelope. This shows that non-centrosomal cues influence centriole duplication and raises the possibility that these external cues could help establish a single duplication site.

scholarly journals The centriole duplication cycle

2014 ◽  
Vol 369 (1650) ◽  
pp. 20130460 ◽  
Author(s):  
Elif Nur Fırat-Karalar ◽  
Tim Stearns
Keyword(s):  
Cell Cycle ◽  
Cell Polarization ◽  
Brain Diseases ◽  
Basal Bodies ◽  
Animal Cells ◽  
Centriole Duplication ◽  
Pericentriolar Material ◽  
Cilia And Flagella ◽  
Duplication Cycle ◽  
Lower Plant

Centrosomes are the main microtubule-organizing centre of animal cells and are important for many critical cellular and developmental processes from cell polarization to cell division. At the core of the centrosome are centrioles, which recruit pericentriolar material to form the centrosome and act as basal bodies to nucleate formation of cilia and flagella. Defects in centriole structure, function and number are associated with a variety of human diseases, including cancer, brain diseases and ciliopathies. In this review, we discuss recent advances in our understanding of how new centrioles are assembled and how centriole number is controlled. We propose a general model for centriole duplication control in which cooperative binding of duplication factors defines a centriole ‘origin of duplication’ that initiates duplication, and passage through mitosis effects changes that license the centriole for a new round of duplication in the next cell cycle. We also focus on variations on the general theme in which many centrioles are created in a single cell cycle, including the specialized structures associated with these variations, the deuterosome in animal cells and the blepharoplast in lower plant cells.

Incorporation of a charged amino acid into the membrane-spanning domain blocks cell surface transport but not membrane anchoring of a viral glycoprotein

1985 ◽  
Vol 5 (6) ◽  
pp. 1442-1448
Author(s):  
G A Adams ◽  
J K Rose
Keyword(s):  
Amino Acid ◽  
Cell Surface ◽  
G Protein ◽  
Abnormal Behavior ◽  
Animal Cells ◽  
Viral Glycoprotein ◽  
Protein Levels ◽  
Membrane Spanning ◽  
Membrane Anchoring ◽  
Isoleucine Residue

The membrane-spanning domain of the vesicular stomatitis virus glycoprotein (G protein) consists of a continuous stretch of 20 uncharged and mostly hydrophobic amino acids. We examined the effects of two mutations which change the amino acid sequence in this domain. These mutations were generated by oligonucleotide-directed mutagenesis of a cDNA clone encoding the G protein, and the altered G proteins were then expressed in animal cells. Replacement of an isoleucine residue in the center of this domain with a strongly polar but uncharged amino acid (glutamine) had no effect on membrane anchoring or transport of the protein to the cell surface. Replacement of this same isoleucine residue with a charged amino acid (arginine) generated a G protein that still spanned intracellular membranes but was not transported efficiently to the cell surface. The protein accumulated in the Golgi region in about 50% of the cells, and about 20% of the cells had detectable protein levels in a punctate pattern on the cell surface. In the remaining cells the protein accumulated in a vesicular pattern throughout the cytoplasm. Models which might explain the abnormal behavior of this protein are discussed.

The effects of D- and L-threo-chloramphenicol on the early development of the chick embryo

Development ◽  
1965 ◽  
Vol 13 (3) ◽  
pp. 341-356
Author(s):  
F. S. Billett ◽  
Rosalba Collini ◽  
Louie Hamilton
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Chick Embryo ◽  
Messenger Rna ◽  
Mammalian Cells ◽  
Animal Cells ◽  
Inhibit Protein Synthesis ◽  
Acid Complex ◽  
Amino Acid Complex ◽  
Bacterial Systems

In many bacterial systems chloramphenicol has been shown to inhibit protein synthesis (Hahn & Wisseman, 1951; Gale & Folkes, 1953). The precise mechanism of this inhibition is not clear, although the evidence suggests that the interaction of the soluble RNA-amino acid complex with the ribosomes is prevented because the attachment of the messenger RNA to the ribosomes is itself impaired (Lacks & Gros, 1959; Nathans & Lipman, 1961; Jardetsky & Julian, 1964; Julian & Jardetsky, 1964). In contrast to its effect on bacterial systems, chloramphenicol has been reported to have little or no action on the protein synthesis by cell-free extracts of mammalian cells (Rendi, 1959; Ehrenstein & Lipmann, 1961). A basis for this resistance has been proposed by Vazquez (1964), who finds that whereas bacterial ribosomes bind chloramphenicol, ribosomes from other organisms do not. Nevertheless, it cannot be stated with any confidence that chloramphenicol has no effect on the protein synthesis of animal cells.

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